n-type silicon

(redirected from ptype)

n-type silicon

The use of n-type and p-type silicon is a foundation concept in the design of transistors. Pure silicon is not conductive. However, it can be made conductive by adding other elements to its crystalline structure, which then become known as "n-type" or "p-type" silicon.

The interaction of n-type and p-type silicon to electric fields and to each other is used to make areas in a transistor change from conductive to non-conductive and vice versa (see crystalline semiconductor). See FET, MOSFET, bipolar transistor and doping.

N-Type (Negative)
N-type silicon is silicon that has been chemically combined (doped) with phosphorus gas to make it conductive. A silicon atom has four electrons in its outer shell and bonds tightly with four surrounding silicon atoms creating a crystal matrix with eight electrons in the outer shells. However, phosphorus has five electrons, and when combined, the fifth electron becomes a "free" electron that moves easily within the crystal when a voltage is applied. Because the charge carriers are electrons, n-type refers to a negative charge.

P-Type (Positive)
In contrast, p-type silicon is silicon doped with boron gas that turns it into a conductive material that readily accepts electrons when voltage is applied. Boron has only three electrons in its outer shell and can bond with only three of the four surrounding silicon atoms. This leaves one silicon atom with a vacant location in its outer shell, called a "hole," that readily accepts an electron. Because the charge carriers are holes, p-type silicon is said to have a positive charge.


N-Type and P-Type
This is a very conceptual illustration of the atomic structure of n-type and p-type silicon. (Image courtesy of TechBites Interactive.)
References in periodicals archive ?
In addition, they suffer from low impedance at Z terminal and poor frequency performance because both Ptype and N-type current mirrors are present in the signal path.
Next, a PTYPE field is transmitted by master ECU_A, and the slave ECU_B and slave ECU_C simultaneously transmits the request ID_B and request ID_C respectively on the communication bus.
A TE module consists of multiple leg pairs, each made of n-type and ptype TE materials, which are connected electrically in series and thermally in parallel to form a TE module.
Zunger, "Intrinsic n-type versus ptype doping asymmetry and the defect physics of ZnO," Physical Review B, vol.
ZnO incorporated yttrium aluminum garnet (YAG) phosphor film was deposited by ultrasonic spray pyrolysis on ptype silicon substrates at atmospheric pressure in nitrogen ([N.sub.2]) gas, at a flow rate of 100 sccm for 20-60 min.
All films were grown at 450[degrees]C and below exhibited ptype behavior.
Llinas, "Ptype calcium channels in the somata and dendrites of adult cerebellar Purkinje cells," Neuron, vol.
These intrinsic organic semiconductors are typically doped oxidatively to form ptype organic semiconductors through dopants.
+ Bits 0-7 Bits 8-15 Bits 16-31 0 Hardware Type (HTYPE) Protocol Type (PTYPE) 32 Hardware Length Protocol Length (PLEN) Operation (OPER) (HLEN) 64 Sender Hardware Address (SHA) 128 Sender Protocol Address (SPA) 160 Target hardware Address (THA) 224 Target Protocol Address (TPA) TABLE 1.
A high-purity grade of Ptype carbon black developed by Cabot Corp.
FIRMSIZE Smaller Largest Midrange POLRISK Highest Lower Lower CULTURE Least similar Midrange Most similar Functional role(s) Usually manu- Manufacturing Manufacturing of joint venture facturing; never and/or marketing; and/or R&D less so R&D marketing; some R&D PTYPE Some All Mostly SOEs firms firms Relative Many 'strong' Many 'strong' Some 'strong' competitive partners; some partners partners position 'weak' partners PERFORMANCE Trivial Trivial Trivial Domicile of Asia, but Japan W-Europe, foreign partner not Japan W-Europe but not or W-Europe Asia Japan Joint venture Asia Japan N-America location W-Europe W-Europe N-America Asia-Pacific SE-Asia Variable D Developed ctry.